2.5-diaminobenzene-arsinic acid.



UNITED STATES PATENT OFFICE.

LUDWIG BENDA, OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOB TO FARBWEBKE VORM. MEISTER LUCIUS & BRlllNING, F HtjCHST-ON-THE-MAIN, GERMANY, A COR- PORATION OF GERMANY.

2.5-DIAMINOBENZENE-ARSINIC ACID.

1 ,040, 260. No Drawing.

Specification of Letters Patent. Application filed February 3, 1912. Serial No. 675,152.

Patented Oct. 8, 1912.

To all whom it may concern Be it known that I, LUDwIc BENDA, Ph. D., chemist, a citizen of the Republic of Switzerland, residing at Fr'ankfort-on-thc- Main, Germany, have invented certain new and useful Improvements in 2.5-Diaminobenzene-Arsimc Acid, of which the following is a s ecification. v

I have ound that by moderately reducing the 2-amino-5-nitrobenzene-arsinic acid, obtainable from para-nitraniiin by heating it with arsenic acid, the 2-5-diaminobenzenearsinic acid can be produced. This body is valuable both for therapeutic purposes and as a parent product for the manutacture of other organic-arseno compounds.

Example: 13 kilos of 5-nitro-2-aminobenzene-l-arsinic acidare dissolved in 80 liters of N. caustic soda-lye and 320 liters of water and mixed, while stirring, at ordinary temperature with 110 liters of ferro-oxidsalt solution (18.9 vol. Fe). The reduction occurs with decoloration of the solution, which is at first yellowish-red. The test of the mixture by curcuma shpuld show throughout an alkaline reaction. The ferruinous mud is filtered OH and to'this filtrate 1s added aquantity of sulfuric acid of 66 B., sufficient to give on Congo-paper a brownish reaction. After having allowed the mixture to stand for a good time, the 2.5-diaminobenzene-l-arsinic acid separated in the form of fine needles, is filtered off.

The new compound is difficultly soluble in cold water, pretty readily soluble in hot water; it readily dissolves in diluted mineral acids, as well as in alkalis and sodium acetate, also in hot acetic acid of 50% strength, but is difiicultly soluble in ethyl alcohol; when heated to 210 C. it assumes a black color and decomposes.

Having now described my invention, what I claim, is:

As a new product, the 2.5-diaminobenzenearsinic acid, being a white crystalline compound, diflicultly soluble in cold water and ethyl-alcohol, readily soluble in hot water and diluted mineral acids, alkalis, and sodium acetate, decomposing when heated to 210 C.

In testimony whereof, I atlix my signature in presence of two witnesses.

LUDWIG BENDA.

Witnesses:

JEAN GRUND, CARL GRUND. 

